1. Field of the Invention
This invention relates to an image processing method and apparatus, in which a direction transforming process for reversing and/or rotating an image signal representing an image of an object is performed in accordance with information giving specifics about an image recording technique, such as the direction from which the image of the object, e.g. a patient, is recorded, and the orientation of the object in the image recording operation. This invention also relates to a recording medium, on which a program for causing a computer to execute the image processing method has been recorded and from which the computer is capable of reading the program.
2. Description of the Prior Art
It has been proposed by the applicant to use stimulable phosphors in radiation image recording and reproducing systems. Specifically, a radiation image of an object, such as a human body, is recorded on a sheet provided with a layer of the stimulable phosphor (hereinafter referred to as a stimulable phosphor sheet). The stimulable phosphor sheet, on which the radiation image has been stored, is then exposed to stimulating rays, such as a laser beam, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to the radiation. The light emitted by the stimulable phosphor sheet, upon stimulation thereof, is photoelectrically detected and converted into an electric image signal. The image signal is then subjected to image processing, such as gradation processing, and the thus obtained processed image signal is used for the reproduction of the radiation image of the object as a visible image on a recording material.
In the radiation image recording and reproducing systems described above, the operation for recording a radiation image of an object is performed with one of various image recording techniques. For example, in cases where a radiation image of the chest of a patient is to be recorded, radiation may be irradiated to the patient from the back side of the patient or from the abdomen side of the patient. Also, in the image recording operation, the patient may stand facing the stimulable phosphor sheet or may stand facing the side opposite to the stimulable phosphor sheet. The image signal having been obtained by reading out the recorded radiation image is subjected to a process for reversing or rotating the radiation image in accordance with the image recording technique, which was employed in the image recording operation, and the image signal having been obtained from the process is utilized for reproducing the radiation image as a visible image. By way of example, in cases where the image recording operation is performed, in which the patient stands facing the stimulable phosphor sheet and radiation is irradiated to the patient from the back side of the patient, the radiation image shown in FIG. 2A is obtained, in which a pattern of the heart is embedded on the left side when the radiation image is seen from the direction of irradiation of the radiation. However, when the radiation image is to be used for making a diagnosis of an illness, it is necessary that the heart pattern is located on the right side as the person, who sees the image, stands facing the image. Therefore, in such cases, as illustrated in FIG. 2B, a process for reversing the right and left sides of the image represented by the original image signal is performed on the original image signal, and a reversed image signal is thereby obtained. The reversed image signal is then utilized for reproducing a visible image. In this manner, a reproduced image, in which the heart pattern is located on the right side as the person, who sees the image, stands facing the image, can be obtained.
An operation for recording a radiation image of an object is often performed by the utilization of a marker for representing the direction from which the image of the object is recorded, the orientation of the object, e.g. a patient, in the image recording operation, or the like. The marker utilized in the image recording operation is formed from a metal, such as lead, which does not transmit radiation. For example, in cases where a radiation image of the chest of a human body is to be obtained, an L-shaped marker may be attached to an upper left corner area of the stimulable phosphor sheet, and the image pattern of the marker may be recorded together with the object image on the stimulable phosphor sheet. In such cases, the radiation image shown in FIG. 3A is obtained, in which the L-shaped marker pattern is embedded at the upper left corner area when the radiation image is seen from the direction of irradiation of the radiation. When the radiation image shown in FIG. 3A is reproduced as a visible image, the right and left sides of the image represented by the original image signal are reversed, and the image shown in FIG. 3B is obtained. In such cases, when a person sees the reproduced image, since the L-shaped marker pattern has been reversed, the person can easily recognize that the right and left sides of the image have been reversed.
Instead of the marker pattern being recorded together with the object image, it may be considered to append a digital marker signal representing the marker pattern to the image signal representing the radiation image. In cases where the marker signal is thus appended to the image signal, a radiation image can be obtained, in which the marker pattern has been appended to a desired position. Also, a marker pattern having an arbitrary shape can be embedded in the radiation image.
However, as described above, the image signal, to which the marker signal is to be appended, is often subjected to the direction transforming process through reversion or rotation in accordance with the information giving specifics about the image recording technique. Therefore, if the marker signal is directly appended to the image signal, which has been obtained from the direction transforming process, the problems described below will occur. Specifically, the problems will occur in that, for example, as illustrated in FIG. 19, in cases where the marker signal is the one representing the L-shaped marker pattern, the image represented by the image signal has been transformed in direction, but the L-shaped marker pattern is appended to the image in the form having not been transformed in direction. Therefore, the person, who sees the radiation image, will misunderstand that the radiation image is the one having not been transformed in direction, and there is the risk that an incorrect diagnosis, or the like, will be made.
The primary object of the present invention is to provide an image processing method, wherein a marker signal is capable of being appended to an image signal in an appropriate state in accordance with specifics about an image recording technique.
Another object of the present invention is to provide an apparatus for carrying out the image processing method.
A further object of the present invention is to provide a recording medium, on which a program for causing a computer to execute the image processing method has been recorded and from which the computer is capable of reading the program.
The present invention provides a first image processing method, in which a direction transforming process is performed on an image signal representing an image and in accordance with information giving specifics about an image recording technique, and in which a marker pattern represented by a marker signal is appended to the image represented by the image signal, the method comprising the steps of:
i) determining a direction of the marker signal and an appending position of the marker signal in accordance with the information giving specifics about the image recording technique, and
ii) appending the marker signal to the image signal in accordance with the thus determined direction of the marker signal and the thus determined appending position of the marker signal.
The term xe2x80x9cspecifics about an image recording techniquexe2x80x9d as used herein means the direction of incidence of radiation in the image recording operation, the orientation (positioning) of an object, such as a patient, the orientation of a stimulable phosphor sheet for storing a radiation image, and the like.
The term xe2x80x9cdirection transforming processxe2x80x9d as used herein means the process for reversing and/or rotating the image signal, such that an image seen from a desired direction can be obtained when the image is reproduced from the image signal having been obtained from the process. The term xe2x80x9crotationxe2x80x9d as used herein means the operation for rotating the image, which is represented by the image signal, by a desired angle around, for example, the center of gravity on the image. The term xe2x80x9creversionxe2x80x9d as used herein means the operation for reversing the image, which is represented by the image signal, symmetrically with respect to, for example, a certain axis.
In the first image processing method in accordance with the present invention, the direction of the marker signal and the appending position of the marker signal are determined in accordance with the information giving specifics about the image recording technique. Specifically, the direction of the marker signal and the appending position of the marker signal are determined such that the direction and the appending position of a marker pattern embedded in a radiation image, which has been obtained by performing an image recording operation by use of a marker and which has then been subjected to a direction transforming process, and the direction and the appending position of the marker pattern embedded in the radiation image, which has been reproduced from the image signal (after being subjected to the direction transforming process) that is appended with the marker signal, may coincide with each other.
The term xe2x80x9cappending a marker signal to an image signalxe2x80x9d as used herein means the operation for replacing the image signal components of the image signal, which correspond to the position to be appended with the marker pattern, by the marker signal, or the operation for appending the marker signal to the image signal as an overlay signal for the image signal. The image signal, to which the marker signal is to be appended, may be the one after being subjected to the direction transforming process. Alternatively, the image signal, to which the marker signal is to be appended, may be the one before being subjected to the direction transforming process.
The first image processing method in accordance with the present invention should preferably be modified such that a size of the marker signal is altered in accordance with a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained.
Also, the first image processing method in accordance with the present invention should preferably be modified such that a marker signal representing a marker pattern having a size adapting to a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained, is selected from a plurality of marker signals, which represent marker patterns having different sizes and having been prepared previously, and
the direction and the appending position of the thus selected marker signal are determined.
Further, the first image processing method in accordance with the present invention should preferably be modified such that, in cases where the image signal components of the image signal, which correspond to the position in the vicinity of the appending position of the marker signal, take signal values (for example, in the cases of 8 bits, 255 or values close to 255) approximately identical with the signal value of the marker signal, the signal value of the marker signal is altered (such that the marker pattern becomes perceptible), and/or the signal values of the image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal, are altered. The marker signal may then be appended to the image signal.
The present invention also provides a second image processing method, in which a direction transforming process is performed on an image signal representing an image and in accordance with information giving specifics about an image recording technique, and in which a marker pattern represented by a marker signal is appended to the image represented by the image signal, the method comprising the steps of:
i) performing the direction transforming process on the image signal,
ii) displaying an image, which is represented by the image signal having been subjected to the direction transforming process, together with a pointer, which indicates an arbitrary position on the image, on displaying means,
iii) altering the direction of the marker signal in accordance with the information giving specifics about the image recording technique,
iv) altering the shape of the pointer to a shape of a marker pattern, which is represented by the altered marker signal,
v) altering the position of the marker pattern on the image in accordance with a pointer position altering instruction, and
vi) appending the marker signal to the image signal in accordance with a marker pattern appending instruction given at a desired position on the image displayed on the displaying means.
The second image processing method in accordance with the present invention should preferably be modified such that a size of the marker signal is altered in accordance with a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained.
Also, the second image processing method in accordance with the present invention should preferably be modified such that a marker signal representing a marker pattern having a size adapting to a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained, is selected from a plurality of marker signals, which represent marker patterns having different sizes and having been prepared previously, and
the direction of the thus selected marker signal is altered.
Further, as in the aforesaid first image processing method in accordance with the present invention, the second image processing method in accordance with the present invention should preferably be modified such that, in cases where the image signal components of the image signal, which correspond to the position in the vicinity of the appending position of the marker signal, take signal values approximately identical with the signal value of the marker signal, the signal value of the marker signal is altered (such that the marker pattern becomes perceptible), and/or the signal values of the image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal, are altered. The marker signal may then be appended to the image signal.
The present invention further provides a first image processing apparatus, which is provided with direction transforming means for performing a direction transforming process on an image signal representing an image and in accordance with information giving specifics about an image recording technique, and in which a marker pattern represented by a marker signal is appended to the image represented by the image signal, the apparatus comprising:
i) determination means for determining a direction of the marker signal and an appending position of the marker signal in accordance with the information giving specifics about the image recording technique, and
ii) marker signal appending means for appending the marker signal to the image signal in accordance with the thus determined direction of the marker signal and the thus determined appending position of the marker signal.
The first image processing apparatus in accordance with the present invention should preferably be modified such that the determination means alters a size of the marker signal in accordance with a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained.
Also, the first image processing apparatus in accordance with the present invention should preferably be modified such that the apparatus further comprises storage means for storing a plurality of marker signals, which represent marker patterns having different sizes and having been prepared previously, and selection means for selecting a marker signal representing a marker pattern having a size adapting to a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained, the selection being made from the plurality of the marker signals, which represent the marker patterns having different sizes and have been stored in the storage means, and
the determination means determines the direction and the appending position of the thus selected marker signal.
Further, the first image processing apparatus in accordance with the present invention should preferably further comprise signal value altering means for operating such that, in cases where a signal value of the marker signal and signal values of image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal, approximately coincide with each other, the signal value altering means alters the signal value of the marker signal and/or the signal values of the image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal.
The present invention still further provides a second image processing apparatus, which is provided with direction transforming means for performing a direction transforming process on an image signal representing an image and in accordance with information giving specifics about an image recording technique, the apparatus comprising:
i) displaying means for displaying an image, which is represented by the image signal having been subjected to the direction transforming process performed by the direction transforming means, together with a pointer, which indicates an arbitrary position on the image,
ii) marker signal altering means for altering a direction of a marker signal, which represents a marker pattern to be appended to the image represented by the image signal, in accordance with the information giving specifics about the image recording technique,
iii) pointer altering means for altering the shape of the pointer to a shape of a marker pattern, which is represented by the altered marker signal,
iv) position altering means for altering the position of the marker pattern on the image in accordance with a pointer position altering instruction, and
v) marker signal appending means for appending the marker signal to the image signal in accordance with a marker pattern appending instruction given at a desired position on the image displayed on the displaying means.
The second image processing apparatus in accordance with the present invention should preferably be modified such that the determination means alters a size of the marker signal in accordance with a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained.
Also, the second image processing apparatus in accordance with the present invention should preferably be modified such that the apparatus further comprises storage means for storing a plurality of marker signals, which represent marker patterns having different sizes and having been prepared previously, and selection means for selecting a marker signal representing a marker pattern having a size adapting to a size of the image, which is represented by the image signal, and/or a read-out density, with which the image signal was obtained, the selection being made from the plurality of the marker signals, which represent the marker patterns having different sizes and have been stored in the storage means, and
the marker signal altering means alters the direction of the thus selected marker signal.
Further, the second image processing apparatus in accordance with the present invention should preferably further comprise signal value altering means for operating such that, in cases where a signal value of the marker signal and signal values of image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal, approximately coincide with each other, the signal value altering means alters the signal value of the marker signal and/or the signal values of the image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal.
The present invention also provides a recording medium, on which a program for causing a computer to execute the first image processing method in accordance with the present invention has been recorded and from which the computer is capable of reading the program.
The present invention further provides a recording medium, on which a program for causing a computer to execute the second image processing method in accordance with the present invention has been recorded and from which the computer is capable of reading the program.
With the first image processing method and apparatus in accordance with the present invention, in cases where the marker pattern, which is represented by the marker signal, is to be appended to the image represented by the image signal, the direction of the marker signal and the appending position of the marker signal are determined in accordance with the information giving specifics about the image recording technique. At this time, the direction of the marker signal and the appending position of the marker signal are determined such that the direction and the appending position of a marker pattern embedded in a radiation image, which has been obtained by performing an image recording operation by use of a marker, and the direction and the appending position of the marker pattern embedded in the radiation image having been reproduced from the image signal appended with the marker signal may coincide with each other. Therefore, in accordance with the direction transforming process performed on the image signal, the marker pattern represented by the marker signal can be appended to the image represented by the image signal in the same manner as that in the cases where the image recording operation is performed by use of a marker. Accordingly, the problems can be prevented from occurring in that the person, who sees the radiation image, misunderstands the reversion of the radiation image or the direction of rotation of the radiation image and makes an incorrect diagnosis, or the like.
With the second image processing method and apparatus in accordance with the present invention, the image, which is represented by the image signal having been subjected to the direction transforming process, is displayed on the displaying means. Also, the direction of the marker signal is altered in accordance with the information giving specifics about the image recording technique. Further, the shape of the pointer, which is displayed on the displaying means, is altered to the shape of the marker pattern, which is represented by the direction-altered marker signal. Thereafter, the position of the marker pattern on the image is altered in accordance with the pointer position altering instruction. Further, the marker signal is appended to the image signal in accordance with the marker pattern appending instruction given at a desired position on the image displayed on the displaying means. Therefore, the image in the state in which the marker pattern is appended can be confirmed on the displaying means, and the marker pattern appending position can be determined easily.
With the first image processing method and apparatus in accordance with the present invention and the second image processing method and apparatus in accordance with the present invention, wherein the size of the marker signal is altered in accordance with the size of the image, which is represented by the image signal, and/or the read-out density, with which the image signal was obtained, the marker pattern adapting to the size of the image, which is represented by the image signal, and/or the read-out density, with which the image signal was obtained, can be displayed on the image. Therefore, the marker pattern which is easy to see can be obtained.
With the first image processing method and apparatus in accordance with the present invention and the second image processing method and apparatus in accordance with the present invention, the marker signal representing the marker pattern having the size adapting to the size of the image, which is represented by the image signal, and/or the read-out density, with which the image signal was obtained, may be selected from a plurality of marker signals, which represent marker patterns having different sizes and having been prepared previously, and the direction and the appending position of the thus selected marker signal may be determined, or the direction of the thus selected marker signal may be altered. In such cases,the marker pattern having the size adapting to the size of the image, which is represented by the image signal, and/or the read-out density, with which the image signal was obtained, can be displayed on the image. Therefore, the marker pattern which is easy to see can be obtained.
With the first image processing method and apparatus in accordance with the present invention and the second image processing method and apparatus in accordance with the present invention, in cases where the signal value of the marker signal and the signal values of image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal, approximately coincide with each other, the signal value of the marker signal and/or the signal values of the image signal components of the image signal, which image signal components correspond to the position in the vicinity of the appending position of the marker signal, may be altered. In such cases, for example, when a white marker pattern is appended to a white region in the image, the marker pattern can be kept easy to see.